/**
 * \file
 * Functions and types for CRC checks.
 *
 * Generated on Mon May 11 20:55:06 2020
 * by pycrc v0.9.2, https://pycrc.org
 * using the configuration:
 *  - Width         = 16
 *  - Poly          = 0x8005
 *  - XorIn         = 0xc55c
 *  - ReflectIn     = True
 *  - XorOut        = 0x0000
 *  - ReflectOut    = True
 *  - Algorithm     = table-driven
 */
#include "custom_crc16.h"     /* include the header file generated with pycrc */
#include <stdlib.h>
#include <stdint.h>



/**
 * Static table used for the table_driven implementation.
 */
static const crc16_t crc16_table[256] = {
        0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241,
        0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440,
        0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40,
        0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841,
        0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40,
        0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41,
        0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641,
        0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040,
        0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240,
        0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441,
        0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41,
        0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840,
        0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41,
        0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40,
        0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640,
        0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041,
        0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240,
        0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441,
        0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41,
        0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840,
        0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41,
        0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40,
        0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640,
        0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041,
        0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241,
        0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440,
        0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40,
        0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841,
        0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40,
        0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41,
        0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641,
        0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040
};


crc16_t crc16_update(crc16_t crc, const void *data, size_t data_len)
{
    const unsigned char *d = (const unsigned char *)data;
    unsigned int tbl_idx;

    while (data_len--) {
        tbl_idx = (crc ^ *d) & 0xff;
        crc = (crc16_table[tbl_idx] ^ (crc >> 8)) & 0xffff;
        d++;
    }
    return crc & 0xffff;
}



#include <stdio.h>
#include <getopt.h>
#include <stdbool.h>
#include <string.h>

static uint8_t str[] = {
        0xAA, 0x1A, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00,
        0x22, 0x11,
};
static bool verbose = false;


static int get_crc16_config(int argc, char *argv[])
{
    int c;
    int option_index;
    static struct option long_options[] = {
            {"verbose",         0, 0, 'v'},
            {0, 0, 0, 0}
    };

    while (1) {
        option_index = 0;

        c = getopt_long(argc, argv, "w:p:n:i:u:o:s:vt", long_options, &option_index);
        if (c == -1)
            break;

        switch (c) {
            case 0:
                printf("option %s", long_options[option_index].name);
                if (optarg)
                    printf(" with arg %s", optarg);
                printf("\n");
                break;
            case 'v':
                verbose = true;
                break;
            case '?':
                return -1;
            case ':':
                fprintf(stderr, "missing argument to option %c\n", c);
                return -1;
            default:
                fprintf(stderr, "unhandled option %c\n", c);
                return -1;
        }
    }

    return 0;
}


static void print_crc16_params(void)
{
    char format[20];

    snprintf(format, sizeof(format), "%%-16s = 0x%%0%dllx\n", (unsigned int)(16 + 3) / 4);
    printf("%-16s = %d\n", "width", (unsigned int)16);
    printf(format, "poly", (unsigned long long int)0x8005);
    printf("%-16s = %s\n", "reflect_in", "true");
    printf(format, "xor_in", (unsigned long long int)0xc55c);
    printf("%-16s = %s\n", "reflect_out", "true");
    printf(format, "xor_out", (unsigned long long int)0x0000);
    printf(format, "crc_mask", (unsigned long long int)0xffff);
    printf(format, "msb_mask", (unsigned long long int)0x8000);
}


/**
 * C main function.
 * \param[in] argc the number of arguments in \a argv.
 * \param[in] argv a NULL-terminated array of pointers to the argument strings.
 * \retval 0 on success.
 * \retval >0 on error.
 */
int main16(int argc, char *argv[])
{
    crc16_t crc;

    get_crc16_config(argc, argv);
    crc = crc16_init();
    crc = crc16_update(crc, (void *)str, sizeof(str));
    crc = crc16_finalize(crc);

    if (verbose) {
        print_crc16_params();
    }
    printf("0x%llx\n", (unsigned long long int)crc);
    return 0;
}
